Catalyst Composition

ABSTRACT

The present invention provides an improved catalyst and a method for its manufacture. The catalyst comprises an acidic, porous crystalline material and has a Proton Density Index of greater than about 1.0, for example from greater than 1.0 to about 2.0, e.g. from about 1.01 to about 1.85. This catalyst may be used to effect conversion in chemical reactions, and is particularly useful in a process for selectively producing a monoalkylated aromatic compound comprising the step of contacting an alkylatable aromatic compound with an alkylating agent under at least partial liquid phase conditions. The acidic, porous crystalline material of the catalyst may comprise an acidic, crystalline molecular sieve having the structure of zeolite Beta, an MWW structure type material, e.g. MCM-22, MCM-36, MCM-49 MCM-56, or a mixture thereof.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a U.S. national stage application under 35 U.S.C. 371 ofInternational Application PCT/US2006/017733 having an internationalfiling date of 8 May 2006. The above application is fully incorporatedherein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to an improved catalyst composition. Thecatalyst may be used to effect various chemical conversions, and isparticularly valuable for use in a process for producing alkylaromatics,particularly ethylbenzene and cumene, or for use in a process foroligomerization of olefins, particularly for production of dimers,trimers and tetramers of olefins, e.g. ethylene, propylene, butylene, ormixtures thereof.

Ethylbenzene and cumene are valuable commodity chemicals that are usedindustrially for the production of styrene monomer and coproduction ofphenol and acetone respectively. Ethylbenzene may be produced by anumber of different chemical processes but one process that has achieveda significant degree of commercial success is the vapor phase alkylationof benzene with ethylene in the presence of a solid, acidic ZSM-5zeolite catalyst. Examples of such ethylbenzene production processes aredescribed in U.S. Pat. No. 3,751,504 (Keown), U.S. Pat. No. 4,547,605(Kresge), and U.S. Pat. No. 4,016,218 (Haag).

More recently focus has been directed at liquid phase processes forproducing ethylbenzene from benzene and ethylene since liquid phaseprocesses operate at a lower temperature than their vapor phasecounterparts and hence tend to result in lower yields of by-products.For example, U.S. Pat. No. 4,891,458 (Innes) describes the liquid phasesynthesis of ethylbenzene with zeolite Beta, whereas U.S. Pat. No.5,334,795 (Chu) describes the use of MCM-22 in the liquid phasesynthesis of ethylbenzene.

Cumene has for many years been produced commercially by the liquid phasealkylation of benzene with propylene over a Friedel-Craft catalyst,particularly solid phosphoric acid or aluminum chloride. More recently,however, zeolite-based catalyst systems have been found to be moreactive and selective for propylation of benzene to cumene. For example,U.S. Pat. No. 4,992,606 (Kushnerick) describes the use of MCM-22 in theliquid phase alkylation of benzene with propylene.

Alkylation processes for producing ethylbenzene and cumene in thepresence of currently used catalysts inherently produce polyalkylatedspecies as well as the desired monoalkylated product. The polyalkylatedspecies are typically transalkylated with benzene to produce additionalmonoalkylated product, for example ethylbenzene or cumene, either byrecycling the polyalkylated species to the alkylation reactor or, morefrequently, by feeding the polyalkylated species to a separatetransalkylation reactor having a transalkylation catalyst. Examples ofcatalysts which have been used in the alkylation of aromatic species,such as alkylation of benzene with ethylene or propylene, and in thetransalkylation of polyalkylated species, such as polyethylbenzenes andpolyisopropylbenzenes, are listed in U.S. Pat. No. 5,557,024 (Cheng) andinclude MCM-22, PSH-3, SSZ-25, zeolite X, zeolite Y, zeolite Beta, aciddealuminized mordenite and TEA-mordenite. Transalkylation over a smallcrystal (<0.5 micron) form of TEA-mordenite is also disclosed in U.S.Pat. No. 6,984,764.

Where the alkylation step is performed in the liquid phase, it is alsodesirable to conduct the transalkylation step under liquid phaseconditions. However, by operating at relatively low temperatures, liquidphase processes impose increased requirements on the catalyst,particularly in the transalkylation step where the bulky polyalkylatedspecies must be converted to additional monoalkylated product withoutproducing unwanted by-products. This has proved to be a significantproblem in the case of cumene production where existing catalysts haveeither lacked the desired activity or have resulted in the production ofsignificant quantities of by-products such as ethylbenzene andn-propylbenzene.

According to the present invention, it has now unexpectedly been foundthat a specific catalyst manufactured to exhibit a Proton Density Index(“PDI”), as herein defined, of greater than 1.0, for example, fromgreater than 1.0 to about 2.0, e.g. from about 1.01 to about 1.85, has aunique combination of activity and, importantly, selectivity, especiallywhen used as a liquid phase alkylation catalyst for manufacture ofmonoalkylated product, particularly for the liquid phase alkylation ofbenzene to ethylbenzene, cumene or sec-butylbenzene. This obviates orreduces the demand in many instances for the difficult transalkylationreaction for conversion of unwanted bulky polyalkylated species.

SUMMARY OF THE INVENTION

According to one aspect of the invention, there is provided an improvedcatalyst. This catalyst may be used to effect conversion in chemicalreactions, and is particularly useful in a process for selectivelyproducing a desired monoalkylated aromatic compound comprising the stepof contacting an alkylatable aromatic compound with an alkylating agentin the presence of the present catalyst under at least partial liquidphase conditions, said catalyst comprising an acidic, porous crystallinematerial and having a PDI of greater than 1.0, for example, from greaterthan 1.0 to about 2.0, e.g. from about 1.01 to about 1.85. Anotheraspect of the present invention is an improved alkylation catalyst foruse in a process for the selective production of monoalkyl benzenecomprising the step of reacting benzene with an alkylating agent underalkylation conditions in the presence of said alkylation catalyst whichcomprises an acidic, porous crystalline material and having a PDI ofgreater than 1.0, for example, from greater than 1.0 to about 2.0, e.g.from about 1.01 to about 1.85. The catalyst may comprise, for example,an acidic, crystalline molecular sieve having the structure of zeoliteBeta, or one having an X-ray diffraction pattern including d-spacingmaxima at 12.4±0.25, 6.9±0.15, 3.57±0.07 and 3.42±0.07 Angstroms, saidcatalyst having a PDI of greater than 1.0, for example, from greaterthan 1.0 to about 2.0, e.g. from about 1.01 to about 1.85. Moreparticularly, the catalyst may comprise an acidic, crystalline molecularsieve having the structure of zeolite Beta, an MWW structure typematerial, e.g. MCM-22, or a mixture thereof.

For use of the present catalyst to effect alkylation of an alkylatablearomatic compound, the alkylating agent may include an alkylatingaliphatic group having 1 to 5 carbon atoms. The alkylating agent maycomprise, for example, ethylene, propylene, and/or the butenes, and thealkylatable aromatic compound in such an instance may comprise benzene.

A preferred catalyst of the present invention comprises an MWW structuretype material, such as for example an acidic, crystalline silicatehaving the structure of MCM-22, PSH-3, SSZ-25, ERB-1, ITQ-1, ITQ-2,ITQ-30, MCM-36, MCM-49, MCM-56 and mixtures thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the shallow bed CAVERN device used in experiments involvingthe present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to an improved catalyst for use inprocesses benefiting from high activity and/or selectivity. One suchprocess involves production of monoalkylated aromatic compounds,particularly ethylbenzene, cumene, and sec-butylbenzene, by the liquidor partial liquid phase alkylation of alkylatable aromatic compound,particularly benzene. Another such process involves production ofoligomers from olefins. More particularly, the present catalystcomposition comprises an acidic, porous crystalline material and ismanufactured to exhibit a PDI of greater than 1.0, for example, fromgreater than 1.0 to about 2.0, e.g. from about 1.01 to about 1.85.

As used herein, the term PDI when used in connection with a particularcatalyst composition is defined as the proton density of the new,treated, catalyst composition measured at a given temperature, dividedby the proton density of the original, untreated, catalyst compositionmeasured at the same given temperature.

As used herein, the term “proton density” means the millimoles (mmol) ofacidic protons and/or non-acidic protons per gram of catalystcomposition. The proton density of the new, treated catalystcomposition, and the proton density of the original, untreated catalystcomposition are both measured at the same temperature, for example roomtemperature, e.g. from about 20° C. to about 25° C.

The amount of protons on a catalyst sample is measured by a solid-statenuclear magnetic resonance method for characterizing the amount ofacidic protons and non-acidic protons on such catalyst sample asdescribed herein. These acidic and non-acidic protons may be present asany hydrogen-containing moiety, or proton-containing moiety, including,but not limited to H, H⁺, OH, OH⁻, and other species. The nuclearmagnetic resonance method includes, but is not limited to, magic anglespinning (MAS) NMR. Sample preparation is the key in NMR measurement ofthe amount of such protons on the catalyst samples. A trace amount ofwater will strongly distort the ¹H NMR intensity due in part to the fast¹H chemical exchange involving Bronsted acid sites and a water molecule.

The method for producing the present catalyst composition comprises thesteps of:

-   -   (a) providing a first, untreated catalyst, i.e. one not having        been treated according to steps (b) and (c) of this invention,        comprising an acidic, porous crystalline material, said first        catalyst having a first hydration state measured in millimoles        (mmol) of protons per gram of catalyst;    -   (b) contacting the first catalyst of step (a) with water in        liquid or gaseous form, at a contact temperature of up to about        500° C., such as from about 1° C. to about 500° C., preferably        from about 1° C. to about 99° C., for a contact time of at least        about 1 second, preferably from about 1 minute to about 60        minutes, to generate a second catalyst having a second hydration        state measured in mmol of protons per gram of catalyst, said        second hydration state being greater than said first hydration        state, i.e. the product of step (b) has a higher proton density        than the step (a) catalyst; and    -   (c) drying the second catalyst resulting from step (b) at a        drying temperature of up to about 550° C., preferably from about        20° C. to about 550° C., more preferably from about 100° C. to        about 200° C., for a drying time of at least about 0.01 hour,        preferably from about 0.1 to about 24 hours, more preferably        from about 1 to about 6 hours, to generate the catalyst        composition having a third hydration state measured in mmol of        protons per gram of catalyst between said first and second        hydration states. The step (c) product will have a Proton        Density Index of greater than 1.0, for example, from greater        than 1.0 to about 2.0, e.g. from about 1.01 to about 1.85.

During drying step (c), acidic protons and/or non-acidic protons areremoved from the catalyst contacted with water in liquid or gaseous formin accordance with step (b). However, care must be taken during dryingstep (c) to avoid removal of essentially all acidic and/or non-acidicprotons of the catalyst resulting from step (b). The hydration state ofthe step (c) product will be higher than that of the starting step (a)catalyst and lower than that of the step (b) product. It is recognizedthat increases in proton density are not simply the conversion of Lewisacid sites to Bronsted acid sites. Not wishing to be bound by any theoryof operation, it is believed that contacting a catalyst comprising anacidic, porous crystalline material and having a first hydration statewith water in liquid or gaseous form under certain contact time andtemperature conditions creates a catalyst having a second hydrationstate higher than the first hydration state. This, followed by dryingunder certain controlled drying time and temperature conditions maychange the nature, type, and/or the amount of acidic and/or non-acidicprotons on such catalyst which are associated with the chemicalreaction, to generate a catalyst composition having a third hydrationstate between that of the first and second hydration states, whereby thecatalyst composition will have a Proton Density Index of greater thanabout 1.0. That is, such catalyst comprising an acidic, porouscrystalline material and treated by the method of this invention has agreater proton density, and/or a greater number of acidic and/ornon-acidic protons as compared to the same catalyst which is not treatedby such method. In other words, PDI is defined as the proton density ofthe third hydration state catalyst composition divided by the protondensity of that catalyst in the first hydration state, both prepared andmeasured in the same manner.

The term “aromatic” in reference to the alkylatable aromatic compoundswhich may be useful as feedstock in a process beneficially utilizing thepresent catalyst is to be understood in accordance with itsart-recognized scope. This includes alkyl substituted and unsubstitutedmono- and polynuclear compounds. Compounds of an aromatic character thatpossess a heteroatom may also be useful.

Substituted aromatic compounds that can be alkylated herein must possessat least one hydrogen atom directly bonded to the aromatic nucleus. Thearomatic rings can be substituted with one or more alkyl, aryl, alkaryl,alkoxy, aryloxy, cycloalkyl, halide, and/or other groups that do notinterfere with the alkylation reaction.

Suitable aromatic compounds include benzene, naphthalene, anthracene,naphthacene, perylene, coronene, and phenanthrene, with benzene beingpreferred.

Generally the alkyl groups that can be present as substituents on thearomatic compound contain from 1 to about 22 carbon atoms and usuallyfrom about 1 to 8 carbon atoms, and most usually from about 1 to 4carbon atoms.

Suitable alkyl substituted aromatic compounds include toluene, xylene,isopropylbenzene, n-propylbenzene, alpha-methylnaphthalene,ethylbenzene, mesitylene, durene, cymenes, butylbenzene, pseudocumene,o-diethylbenzene, m-diethylbenzene, p-diethylbenzene, isoamylbenzene,isohexylbenzene, pentaethylbenzene, pentamethylbenzene,1,2,3,4-tetraethylbenzene, 1,2,3,5-tetramethylbenzene,1,2,4-triethylbenzene, 1,2,3-trimethylbenzene, m-butyltoluene,p-butyltoluene, 3,5-diethyltoluene, o-ethyltoluene, p-ethyltoluene,m-propyltoluene, 4-ethyl-m-xylene, dimethylnaphthalenes,ethylnaphthalene, 2,3-dimethylanthracene, 9-ethylanthracene,2-methylanthracene, o-methylanthracene, 9,10-dimethylphenanthrene, and3-methyl-phenanthrene. Higher molecular weight alkylaromatic compoundscan also be used as starting materials and include aromatic hydrocarbonssuch as are produced by the alkylation of aromatic hydrocarbons witholefin oligomers. Such products are frequently referred to in the art asalkylate and include hexylbenzene, nonylbenzene, dodecylbenzene,pentadecylbenzene, hexyltoluene, nonyltoluene, dodecyltoluene,pentadecytoluene, etc. Very often alkylate is obtained as a high boilingfraction in which the alkyl group attached to the aromatic nucleusvaries in size from about C₆ to about C₁₂. When cumene or ethylbenzeneis the desired product, the present process produces acceptably littleby-products such as xylenes. The xylenes made in such instances may beless than about 500 ppm.

Reformate containing a mixture of benzene, toluene and/or xyleneconstitutes a particularly useful feed for an alkylation processbeneficially utilizing the present catalyst.

The alkylating agents which are useful as feedstock in a processbeneficially utilizing the catalyst of this invention generally includeany aliphatic or aromatic organic compound having one or more availablealkylating aliphatic groups capable of reaction with the alkylatablearomatic compound, preferably with the alkylating group possessing from1 to 5 carbon atoms. Examples of suitable alkylating agents are olefinssuch as ethylene, propylene, the butenes (including 1-butene, 2-butenes,and mixtures thereof), and the pentenes; alcohols (inclusive ofmonoalcohols, dialcohols, trialcohols, etc.) such as methanol, ethanol,the propanols, the butanols, and the pentanols; aldehydes such asformaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, andn-valeraldehyde; and alkyl halides such as methyl chloride, ethylchloride, the propyl chlorides, the butyl chlorides, and the pentylchlorides, and so forth.

Mixtures of light olefins are useful as alkylating agents in thealkylation process utilizing the catalyst of this invention. Also, suchmixtures of light olefins are useful as reactants in the oligomerizationprocesses of this invention. Accordingly, mixtures of ethylene,propylene, butenes, and/or pentenes which are major constituents of avariety of refinery streams, e.g., fuel gas, gas plant off-gascontaining ethylene, propylene, etc., naphtha cracker off-gas containinglight olefins, refinery FCC propane/propylene streams, etc., are usefulalkylating agents and oligomerization reactants. For example, a typicalFCC light olefin stream possesses the following composition:

Wt. % Mole % Ethane 3.3 5.1 Ethylene 0.7 1.2 Propane 4.5 15.3 Propylene42.5 46.8 Isobutane 12.9 10.3 n-Butane 3.3 2.6 Butenes 22.1 18.32Pentanes 0.7 0.4

For these uses of the present catalyst, products may includeethylbenzene from the reaction of benzene with ethylene, cumene from thereaction of benzene with propylene, ethyltoluene from the reaction oftoluene with ethylene, cymenes from the reaction of toluene withpropylene, and sec-butylbenzene from the reaction of benzene andn-butenes, a mixture of heavier olefins from the oligomerization oflight olefins. Particularly preferred uses of the present catalystrelate to the production of cumene by the alkylation of benzene withpropylene, production of ethylbenzene by the alkylation of benzene withethylene, production of sec-butylbenzene by the alkylation of benzenewith butenes, and oligomerization of ethylene, propylene, butylene, ormixtures thereof.

The organic conversion processes contemplated for use of the catalyst ofthis invention include, but are not limited to, alkylation of aromaticcompounds and oligomerization of olefins and may be conducted such thatthe reactants are brought into contact with the required catalyst in asuitable reaction zone such as, for example, in a flow reactorcontaining a fixed bed of the catalyst composition, under effectiveconversion conditions. Such conditions include a temperature of fromabout 0° C. to about 1000° C., preferably from about 0° C. to about 800°C., a pressure of from about 10.1 kPa-a (0.1 atmosphere) to about100,000 kPa-a (1000 atmospheres), preferably from about 12.5 kPa-a(0.125 atmospheres) to about 50,000 kPa-a (500 atmospheres), and a feedweight hourly space velocity (WHSV) of from about 0.01 to 500 hr⁻¹,preferably from about 0.1 to about 100 hr⁻¹. If a batch reactor is used,the reaction time will be from about 1 minute to about 100 hours,preferably from about 1 hour to about 10 hours.

An alkylation process utilizing the catalyst of this invention may beconducted such that the organic reactants, i.e., the alkylatablearomatic compound and the alkylating agent, are brought into contactwith the present catalyst in a suitable reaction zone such as, forexample, in a flow reactor containing a fixed bed of the catalystcomposition, under effective alkylation conditions. Such conditionsinclude a temperature of from about 0° C. to about 500° C., preferablyfrom about 10° C. to about 260° C., a pressure of from about 20 kPa-a(0.2 atmospheres) to about 25,000 kPa-a (250 atmospheres), preferablyfrom about 101 kPa-a (1 atmospheres) to about 5,500 kPa-a (55atmospheres), a molar ratio of alkylatable aromatic compound toalkylating agent of from about 0.1:1 to about 50:1, preferably fromabout 0.5:1 to about 10:1, and a feed weight hourly space velocity(WHSV) based on the alkylating agent of from about 0.1 to 500 hr⁻¹,preferably from about 0.5 to about 100 hr⁻¹.

The reactants can be in either the vapor phase or partially orcompletely in the liquid phase and can be neat, i.e. free fromintentional admixture or dilution with other material, or they can bebrought into contact with the alkylation catalyst composition with theaid of carrier gases or diluents such as, for example, hydrogen ornitrogen.

When benzene is alkylated with ethylene to produce ethylbenzene, thealkylation reaction is preferably carried out in the liquid phase underconditions including a temperature of from about 150° C. to about 300°C., more preferably from about 170° C. to about 260° C.; a pressure upto about 20,000 kPa-a (200 atmospheres), more preferably from about2,000 kPa-a (20 atmospheres) to about 5,500 kPa-a (55 atmospheres); aweight hourly space velocity (WHSV) based on the ethylene alkylatingagent of from about 0.1 to about 20 hr⁻¹, more preferably from about 0.5to about 6 hr⁻¹; and a ratio of benzene to ethylene in the alkylationreactor of from about 0.5:1 to about 30:1 molar, more preferably fromabout 1:1 to about 10:1 molar.

When benzene is alkylated with propylene to produce cumene, the reactionmay also take place under liquid phase conditions including atemperature of up to about 250° C., preferably up to about 150° C.,e.g., from about 10° C. to about 125° C.; a pressure of about 25,000kPa-a (250 atmospheres) or less, e.g., from about 101 kPa-a (1atmosphere) to about 3,000 kPa-a (30 atmospheres); a weight hourly spacevelocity (WHSV) based on propylene alkylating agent of from about 0.1hr⁻¹ to about 250 hr⁻¹, preferably from about 1 hr⁻¹ to about 50 hr⁻¹;and a ratio of benzene to propylene in the alkylation reactor of fromabout 0.5:1 to about 30:1 molar, more preferably from about 1:1 to about10:1 molar.

When benzene is alkylated with an alkylating agent selected from thegroup consisting of 1-butene, 2-butene and mixtures thereof, to producesec-butylbenzene, the reaction may also take place under liquid phaseconditions including a temperature of from about 50 to about 250° C.,preferably from about 100 to about 200° C.; a pressure of about 350kPa-a (3.5 atmospheres) to about 3,500 kPa-a (35 atmospheres),preferably from about 700 kPa-a (7 atmospheres) to about 2,700 kPa-a (27atmospheres); a WHSV based on the butene alkylating agent of from about0.1 to about 20 hr⁻¹, preferably from about 1 to about 10 hr⁻¹; and aratio of benzene to the butene alkylating agent from about 1:1 to about10:1, preferably from about 1:1 to about 4:1 molar.

The catalyst of the present invention may comprise one or more acidic,porous crystalline materials or molecular sieve having the followingstructures: of zeolite Beta (described in U.S. Pat. No. 3,308,069); oran MWW structure type such as, for example, those having an X-raydiffraction pattern including d-spacing maxima at 12.4±0.25, 6.9±0.15,3.57±0.07 and 3.42±0.07 Angstroms.

As used herein, an “acidic, porous crystalline material” means a porouscrystalline material or molecular sieve containing acidic protonssufficient to catalyze hydrocarbon conversion reactions.

Examples of MWW structure type materials include MCM-22 (described inU.S. Pat. No. 4,954,325), PSH-3 (described in U.S. Pat. No. 4,439,409),SSZ-25 (described in U.S. Pat. No. 4,826,667), ERB-1 (described inEuropean Patent No. 0293032), ITQ-1 (described in U.S. Pat. No.6,077,498), ITQ-2 (described in U.S. Pat. No. 6,231,751), ITQ-30(described in WO 2005-118476), MCM-36 (described in U.S. Pat. No.5,250,277), MCM-49 (described in U.S. Pat. No. 5,236,575) and MCM-56(described in U.S. Pat. No. 5,362,697). The catalyst can include themolecular sieve in unbound or self-bound form or, alternatively, themolecular sieve can be combined in a conventional manner with an oxidebinder as hereinafter detailed. For certain applications of thecatalyst, the average particle size of the catalyst or the acidic,porous crystalline materials or molecular sieve component may be fromabout 0.05 to about 200 microns, for example, from 20 to 200 microns.

When used as catalyst for alkylation, the alkylation reactor effluentcontains the excess aromatic feed, monoalkylated product, polyalkylatedproducts, and various impurities. The aromatic feed is recovered bydistillation and recycled to the alkylation reactor. Usually a smallbleed is taken from the recycle stream to eliminate unreactiveimpurities from the loop. The bottoms from the distillation may befurther distilled to separate monoalkylated product from polyalkylatedproducts and other heavies.

The polyalkylated products separated from the alkylation reactoreffluent may be reacted with additional aromatic feed in atransalkylation reactor, separate from the alkylation reactor, over asuitable transalkylation catalyst. The transalkylation catalyst maycomprise one or a mixture of acidic, porous, crystalline materials ormolecular sieves having the structure of zeolite Beta, zeolite Y,mordenite or an MWW structure type material having an X-ray diffractionpattern including d-spacing maxima at 12.4±0.25, 6.9±0.15, 3.57±0.07 and3.42±0.07 Angstroms.

The X-ray diffraction data used to characterize said above catalyststructures are obtained by standard techniques using the K-alpha doubletof copper as the incident radiation and a diffractometer equipped with ascintillation counter and associated computer as the collection system.Materials having the above X-ray diffraction lines include, for example,MCM-22 (described in U.S. Pat. No. 4,954,325), PSH-3 (described in U.S.Pat. No. 4,439,409), SSZ-25 (described in U.S. Pat. No. 4,826,667),ERB-1 (described in European Patent No. 0293032), ITQ-1 (described inU.S. Pat. No. 6,077,498), ITQ-2 (described in U.S. Pat. No. 6,231,751),ITQ-30 (described in WO 2005-118476), MCM-36 (described in U.S. Pat. No.5,250,277), MCM-49 (described in U.S. Pat. No. 5,236,575) and MCM-56(described in U.S. Pat. No. 5,362,697), with MCM-22 being particularlypreferred.

Zeolite Beta is disclosed in U.S. Pat. No. 3,308,069. Zeolite Y andmordenite occur naturally but may also be used in one of their syntheticforms, such as Ultrastable Y (USY), which is disclosed in U.S. Pat. No.3,449,070, Rare earth exchanged Y (REY), which is disclosed in U.S. Pat.No. 4,415,438, and TEA-mordenite (i.e., synthetic mordenite preparedfrom a reaction mixture comprising a tetraethylammonium directingagent), which is disclosed in U.S. Pat. Nos. 3,766,093 and 3,894,104.However, in the case of TEA-mordenite for use in the transalkylationcatalyst, the particular synthesis regimes described in the patentsnoted lead to the production of a mordenite product composed ofpredominantly large crystals with a size greater than 1 micron andtypically around 5 to 10 micron. It has been found that controlling thesynthesis so that the resultant TEA-mordenite has an average crystalsize of less than 0.5 micron results in a transalkylation catalyst withmaterially enhanced activity for liquid phase aromatics transalkylation.

The required small crystal TEA-mordenite for transalkylation can beproduced by crystallization from a synthesis mixture having a molarcomposition within the following ranges:

Useful Preferred R/R + Na⁺ = >0.4 0.45-0.7  OH⁻/SiO₂ = <0.22 0.05-0.2 Si/Al₂ = >30-90 35-50 H₂O/OH =  50-70 50-60

The crystallization is conducted at a temperature of 90 to 200° C., fora time of 6 to 180 hours.

The catalyst of the present invention may include an inorganic oxidematerial matrix or binder. Such matrix materials include synthetic ornaturally occurring substances as well as inorganic materials such asclay, alumina, silica and/or metal oxides. The latter may be eithernaturally occurring or in the form of gelatinous precipitates or gelsincluding mixtures of silica and metal oxides. Naturally occurring clayswhich can be composited with the inorganic oxide material include thoseof the montmorillonite and kaolin families, which families include thesubbentonites and the kaolins commonly known as Dixie, McNamee, Georgiaand Florida clays or others in which the main mineral constituent ishalloysite, kaolinite, dickite, nacrite or anauxite. Such clays can beused in the raw state as originally mined or initially subjected tocalcination, acid treatment or chemical modification.

Specific useful catalyst matrix or binder materials employed hereininclude silica, alumina, zirconia, titania, silica-alumina,silica-magnesia, silica-zirconia, silica-thoria, silica-beryllia,silica-titania as well as ternary compositions such assilica-alumina-thoria, silica-alumina-zirconia, silica-alumina-magnesiaand silica-magnesia-zirconia. The matrix can be in the form of a cogel.A mixture of these components could also be used.

The relative proportions of the acidic, porous, crystalline material ormolecular sieve and binder or matrix, if present, may vary widely withthe crystalline material or molecular sieve content ranging from about 1to about 99 percent by weight, and more usually in the range of about 30to about 80 percent by weight of the total catalyst. Of course, thecatalyst may comprise a self-bound material or molecular sieve or anunbound material or molecular sieve, thereby being about 100% acidic,porous crystalline material or molecular sieve.

The catalyst of the present invention, or its acidic, porous crystallinematerial or molecular sieve component, may or may not contain addedfunctionalization, such as, for example, a metal of Group VI (e.g. Crand Mo), Group VII (e.g. Mn and Re) or Group VIII (e.g. Co, Ni, Pd andPt), or phosphorus.

Experimental Methods

The following equipment and feed pretreatment methods were used in theexperiments described in the non-limiting examples of the invention.

Equipment

A 300 ml Parr batch reaction vessel equipped with a stir rod and staticcatalyst basket was used for the activity and selectivity measurements.The reaction vessel was fitted with two removable vessels for theintroduction of benzene and propylene respectively.

Feed Pretreatment

Commercial grade benzene was pretreated with molecular sieve 13X,molecular sieve 4A, Engelhard F-24 Clay, and Selexsorb CD. Polymer gradepropylene obtained from a commercial specialty gases source waspretreated with molecular sieve 5A and Selexsorb CD. Ultra high puritygrade nitrogen obtained from a commercial specialty gases source waspretreated with molecular sieve 5A and Selexsorb CD. All feedpretreatment materials were dried in a 260° C. oven for 12 hours beforeusing. All references to benzene, propylene and nitrogen, refer to thecommercial grade benzene, the polymer grade propylene, and the ultrahigh purity grade nitrogen, that have been pretreated as describedherein.

The following NMR procedure for determining proton density was used inthe experiments described in the non-limiting examples of the invention.

NMR Procedure for Determining Proton Density

In the present invention, the NMR procedure for determining the protondensity of a catalyst sample is as follows. The proton density of acatalyst sample may be determined using a shallow bed CAVERN device,shown in FIG. 1. In FIG. 1, a CAVERN device is shown which is comprisedof an upper housing 5 and lower housing 6 connected by joint 12, havinga mechanism 11 for lifting a glass trapdoor 16 over a catalyst bed 14,means for a vacuum line 20, and means for heating via thermocouple 13. A5 mm o.d. glass tube 17 slides over a 3 mm stainless steel rod 15, andrests between the endcap 18 and the glass trapdoor 16. The stainlesssteel rod 15 is retracted by turning the mechanism 11, whereby the glasstube 17 raises the glass trapdoor 16 above the catalyst bed 14. Bygently turning or shaking the CAVERN device, the catalyst sample (notshown) falls into the MAS rotor 19. This process works for zeolites andmetal oxide powders. Further details regarding the operation of theCAVERN device are disclosed in Xu, T.; Haw, J. F. Top. Catal. 1997, 4,109-118, incorporated herein by reference.

In order to determine the proton density of a catalyst sample, a thinlayer of the catalyst sample was spread out in the catalyst bed 14 ofthe CAVERN device, and the temperature of the catalyst sample viathermocouple 13 was raised to the desired temperature for evaluating thecatalyst sample (“Specified NMR Pretreatment Temperature”) undersufficient vacuum by vacuum line 20 to remove any moisture absorbed onthe catalyst sample. The catalyst sample was typically held at thedesired temperature for 2 hours under such vacuum prior to NMRmeasurement.

The thus prepared catalyst sample was loaded into a 5 mm NMR rotor, suchas MAS rotor 19, and the rotor was sealed with a Kel-F end cap bymanipulating the CAVERN device. All the operations were performed whilethe catalyst sample was still under vacuum, ensuring the sampleintegrity for NMR study. After the desired NMR spectra were acquired,the weight of MAS rotor 19, the catalyst sample and the endcap 18 wasdetermined followed by weight determination of the rotor and the endcap18 upon unpacking the catalyst sample. The difference in the two weightswas the amount of the catalyst sample in the MAS rotor 19.

¹H NMR experiments were performed on a 400 MHz solid state NMRspectrometer operating at 399.8 MHz for 1H. Quantitative ¹H spectra wereobtained by the use of rotor-synchronized spin-echo sequence(π/2-t_(D1)-π-t_(D2)-Echo) using 8 to 12 kHz spinning speeds. Typically,3.5-μs π/2 pulses, t_(D1) of 125-μs and t_(D2) of 113.1 μs were used fora spinning speed of 9 kHz. Spectra acquired using the solid echosequence showed some background signal, presumably from the spinningmodule and the endcap 18 of the MAS rotor 19. A solid echo sequence withDEPTH removes the background signal from the spectra. The DEPTH sequenceconsisted of a 900 pulse (3.5-μs) followed by two 1800 pulses. Adescription of the DEPTH sequence appears in Corey, D. G.; Ritchey, W.M. J. Magn. Reson. 1988, 80, 128, incorporated herein by reference. Apulse delay of 10 seconds was sufficient for quantifying proton densityof the catalyst samples tested. Acetone was used as secondary standardfor ¹H shift (2.1 ppm). All the reported chemical shifts were referencedto tetramethylsilane (TMS) at 0 ppm.

The proton densities for various “as synthesized” acidic, porouscrystalline materials not yet treated in accordance with the presentinvention, and therefore in the first hydration state, are as follows:

Acidic Porous Crystalline Material Proton Density Zeolite Beta 3.10 mmolprotons/gram zeolite Beta MCM-22 2.24 mmol protons/gram MCM-22 MCM-362.14-2.24 mmol protons/gram MCM-36 MCM-49 2.14 mmol protons/gram MCM-49MCM-56 2.14-2.24 mmol protons/gram MCM-56

Of course, these acidic, porous crystalline materials in the thirdhydration state of having undergone treatment according to the method ofthe present invention would have proton densities greater than thoselisted above for the same material in the first hydration state.

The following method for determination of the Proton Density Index (PDI)was used in the experiments described in the non-limiting examples ofthis invention.

Determination of Proton Density Index

The PDI of a particular catalyst composition is determined from theratio of the proton density of the new, treated catalyst composition tothe proton density of the original, untreated catalyst composition. Suchnew, treated catalyst composition may be treated in accordance with theproton adjustment techniques described herein or other techniques thatalter proton density. Also, such original, untreated catalystcomposition may or may not be treated in accordance with the protonadjustment techniques described herein or other techniques that alterproton density. As noted above, the term “proton density” as used hereinmeans the millimoles (mmol) of acidic protons and/or non-acidic protonsper gram of catalyst composition. The proton density of the new, treatedcatalyst composition, and the proton density of the original, untreatedcatalyst composition are both measured at the same temperature, forexample room temperature, e.g. from about 20° C. to about 25° C.Therefore, the PDI of particular catalyst composition is defined as theproton density of the new, treated, catalyst composition measured at agiven temperature, divided by the proton density of the original,untreated, catalyst composition measured at the same given temperature.

The NMR spectrometer used to determine proton density was a VarianInfinity Plus 400 MHz solid state NMR with an Oxford AS400 magnet.

The following catalyst reactivity testing procedure was used in thenon-limiting examples of the invention.

Catalyst Reactivity Testing Procedure

To prepare a catalyst composition for reactivity testing, a specifiedamount of a catalyst sample was dried in the presence of air in an ovenat a specified ex-situ drying temperature (“Specified Ex-situ DryingTemperature”) for 2 hours. The catalyst sample was removed from the ovenand weighed. Quartz chips were used to line the bottom of a basketfollowed by loading of the catalyst sample into the basket on top of thefirst layer of quartz. Quartz chips were then placed on top of thecatalyst sample. The basket containing the catalyst sample and quartzchips were placed in an oven at the Specified Ex-situ Drying Temperaturein the presence of air for about 16 hours.

The reactor and all lines were cleaned with a suitable solvent (such astoluene) before each experiment. The reactor and all lines were dried inair after cleaning to remove all traces of cleaning solvent. The basketcontaining the catalyst sample and quartz chips were removed from theoven, immediately placed in the reactor, and the reactor was immediatelyassembled. The reactor temperature was set to an in-situ dryingtemperature (“Specified In-situ Drying Temperature”) and purged with 100SCCM of nitrogen for 2 hours.

The reactor temperature was then reduced to 130° C., the nitrogen purgewas discontinued and the reactor vent closed. A 156.1 gram quantity ofbenzene was loaded into a 300 ml (cc) transfer vessel, performed in aclosed system. The benzene vessel was pressurized to 790 kPa-a (100psig) with a nitrogen source and the benzene was transferred into thereactor. The agitator speed was set to 500 rpm and the reactor wasallowed to equilibrate for 1 hour.

A 75 cc Hoke transfer vessel was then filled with 28.1 grams of liquidpropylene and connected to the reactor vessel, and then connected with a2.69 kPa-a (300 psig) nitrogen source. After the one-hour benzene stirtime had elapsed, the propylene was transferred from the Hoke vessel tothe reactor. The 2.69 kPa-a (300 psig) nitrogen source was maintainedconnected to the propylene vessel and open to the reactor during theduration of the test to maintain constant reaction pressure of 2.69kPa-a (300 psig). Liquid product samples were taken at 30, 60, 120, 150,180 and 240 minutes after addition of the propylene. These samples werethen analyzed by Gas Chromatography with a Flame Ionization Detector andprocedures known to those skilled in the art.

In these examples, the selectivity of the catalyst sample (“CatalystSelectivity”) to the desired isopropylbenzene (cumene) product wascalculated as the ratio of isopropylbenzene to diisopropylbenzene(IPB/DIPB) after propylene conversion reached 100%. A higher IPB/DIPBratio means a greater selectivity of the catalyst sample toisopropylbenzene (cumene). Also, in these examples the catalyticactivity of the catalyst samples was determined by calculating the 2ndorder kinetic rate constant using mathematical techniques well known tothose skilled in the art (“Catalyst Activity”).

The following proton content adjustment techniques were used in theexperiments described in the non-limiting examples of the invention.

Proton Content Adjustment Techniques A. Proton Content AdjustmentTechnique #1

In one embodiment of the invention, a sample of catalyst comprising anacidic, porous crystalline material and having a first hydration statemeasured in mmol of protons per gram of catalyst, was placed into asuitable container. Water in liquid form, specifically deionized water,was transferred into the container slowly so as to displace air from thecatalyst sample by filling from the bottom up. Water was added until thecatalyst sample was completely covered with water and the level of thewater was approximately ¼″ above the catalyst sample. The catalystsample and water were allowed to remain undisturbed under theseconditions for a specified contact time (“Contact Time”) of at leastabout 1 second preferably from about 1 minute to about 60 minutes orgreater, to generate a catalyst sample having a second hydration state(measured in mmol of protons per gram of catalyst sample), in which thesaid second hydration state being greater that said first hydrationstate. After the Contact Time, the water was decanted and the catalystsample was allowed to dry in air at ambient conditions for at least 8hours, to generate a catalyst sample having a third hydration state(measured in mmol of protons per gram of catalyst sample).

B. Proton Content Adjustment Technique #2

In another embodiment of the invention, a sample of catalyst is exposedto water in the vapor form (with or without a suitable carrier, such asnitrogen) at a specified contact temperature (“Contact Temperature”) andat a specified contact pressure (“Contact Pressure”).

In still another embodiment of the invention, the catalyst sample thathas first been treated in accordance with Proton Content AdjustmentTechnique #1 is then treated in accordance with Proton ContentAdjustment Technique #2.

In still yet another embodiment of the invention, the catalyst samplethat has first been treated in accordance with Proton Content AdjustmentTechnique #2 is then treated in accordance with Proton ContentAdjustment Technique #1.

Non-limiting examples of the catalyst samples made in accordance withthe methods of this invention, and the use of such catalyst samples inalkylation experiments, are described with reference to the followingexperiments.

Example 1

The catalyst sample of this Example 1 comprised 80 wt % MCM-49 and 20 wt% alumina (Al₂O₃) and its proton density was determined in accordancewith the NMR Procedure for Determining Proton Density, described above,at the Specified NMR Pretreatment Temperature of 250° C. The protondensity was 1.71 mmol per gram of catalyst (first hydration state).

A 0.5 gram portion of the catalyst sample of this Example 1 was testedin accordance with the Catalyst Reactivity Testing Procedure at theSpecified Ex-situ Drying Temperature of 250° C. and the SpecifiedIn-situ Drying Temperature of 170° C. The Catalyst Selectivity of thiscatalyst sample was 5.92, determined as the weight ratio ofisopropylbenzene to diisopropylbenzene (IPB/DIPB). The Catalyst Activityof this catalyst sample was 363.

Example 2

Another portion of the catalyst sample of Example 1 was treated inaccordance with Proton Content Adjustment Technique #1 at a Contact Timeof approximately 1 hour, to produce the treated catalyst sample of thisExample 2 having a third hydration state. The proton density of thethird hydration state of the treated catalyst sample was 1.85 mmol pergram of catalyst (third hydration state), determined in accordance withthe NMR Procedure for Determining Proton Density, described above, atthe Specified NMR Pretreatment Temperature of 250° C.

A 0.5 gram portion of the treated catalyst sample of this Example 2 wastested in accordance with the Catalyst Reactivity Testing Procedure atthe Specified Ex-situ Drying Temperature of 250° C. and the SpecifiedIn-situ Drying Temperature of 170° C. The Catalyst Selectivity of thiscatalyst sample was 6.94, determined as the weight ratio of IPB/DIPB.The Catalyst Activity of this catalyst sample was 383.

The PDI of the catalyst sample of this Example 2 was determined to be1.08, and represents an 8% increase in the proton content (determined asmmol of protons per gram of catalyst) as compared to the catalyst sampleof Example 1. The Catalyst Selectivity (IPB/DIPB) of the catalyst sampleof this Example 2 displayed an increase of 17%, and the CatalystActivity displayed an increase of 5.5%, as compared to the catalystsample of Example 1.

Example 3

The catalyst sample of this Example 3 comprised 80 wt % zeolite Beta and20 wt % alumina and its proton density was determined in accordance withthe NMR Procedure for Determining Proton Density, described above, atthe Specified NMR Pretreatment Temperature of 250° C. The proton densitywas 2.48 mmol per gram of catalyst (first hydration state).

A 1.0 gram portion of the catalyst sample of this Example 3 was testedin accordance with the Catalyst Reactivity Testing Procedure at theSpecified Ex-situ Drying Temperature of 250° C. and the SpecifiedIn-situ Drying Temperature of 170° C. The Catalyst Selectivity of thiscatalyst sample was 5.62, determined as the weight ratio of IPB/DIPB.The Catalyst Activity of this catalyst sample was 23.

Example 4

Another portion of the catalyst sample of Example 3 was treated inaccordance with Proton Content Adjustment Technique #1 at a Contact Timeof approximately 1 hour, to produce a treated catalyst of this Example 4having a third hydration state. The proton density of the treatedcatalyst was 2.77 mmol per gram of catalyst (third hydration state),determined in accordance with the NMR Procedure for Determining ProtonDensity, described above, at the Specified NMR Pretreatment Temperatureof 250° C.

A 1.0 gram portion of the treated catalyst of this Example 4 was testedin accordance with the Catalyst Reactivity Testing Procedure at theSpecified Ex-situ Drying Temperature of 250° C. and the SpecifiedIn-situ Drying Temperature of 170° C. The Catalyst Selectivity of thiscatalyst sample was 9.35, determined as the weight ratio of IPB/DIPB.The Catalyst Activity of this catalyst sample was 4.

The PDI of the catalyst sample of this Example 4 was determined to be1.12, and represents a 12% increase in proton content (determined asmmol of protons per gram of catalyst) as compared to the catalyst sampleof Example 3. The Catalyst Selectivity (IPB/DIPB) of the catalyst sampleof this Example 4 displayed an increase of 66%, and the CatalystActivity was still 17.4% of that of Example 3.

Example 5

The catalyst sample of Example 1 was treated in nitrogen that wassaturated with water vapor in accordance with Proton Content AdjustmentTechnique #2 at a Contact Temperature of 220° C. and a Contact Pressureof 445 kPa-a (50 psig). The resulting catalyst was then treated inaccordance with Proton Content Adjustment Technique #1, to produce thetreated catalyst sample of this Example 5 having a third hydrationstate. The proton density of the treated catalyst was 1.76 mmol per gramof catalyst (third hydration state), determined in accordance with theNMR Procedure for Determining Proton Density, described above, at theSpecified NMR Pretreatment Temperature of 250° C.

A 0.5 gram portion of the treated catalyst of this Example 5 was testedin accordance with the Catalyst Reactivity Testing Procedure at theSpecified Ex-situ Drying Temperature of 250° C. and the SpecifiedIn-situ Drying Temperature of 170° C. The Catalyst Selectivity of thecatalyst sample was 6.80, determined as the weight ratio of IPB/DIPB.The Catalyst Activity of this catalyst sample was 377.

The PDI of the catalyst sample of this Example 5 was determined to be1.03, and represents a 3% increase in proton content (determined as mmolof protons per gram of catalyst), as compared to the catalyst sample ofExample 1. The Catalyst Selectivity (IPB/DIPB) of the catalyst sample ofthis Example 5 displayed an increase of 15%, and the Catalyst Activitydisplayed an increase of 4%, as compared to the catalyst sample ofExample 1.

Example 6

The catalyst sample of this Example 6 comprised 80 wt % MCM-49 and 20 wt% alumina and its proton density was determined in accordance with theNMR Procedure for Determining Proton Density, described above, at theSpecified NMR Pretreatment Temperature of 150° C. The proton density wasfound to be 2.59 mmol per gram of catalyst (first hydration state).

A 0.5 gram portion of the catalyst sample of this Example 6 was testedin accordance with the Catalyst Reactivity Testing Procedure at theSpecified Ex-situ Drying Temperature of 150° C. and the SpecifiedIn-situ Drying Temperature of 150° C. The Catalyst Selectivity of thiscatalyst sample was 5.92, determined as the weight ratio ofisopropylbenzene to diisopropylbenzene (IPB/DIPB). The Catalyst Activityof this catalyst sample was 275.

Example 7

Another portion of the catalyst sample of Example 6 was treated inaccordance with Proton Content Adjustment Technique #1 at a Contact Timeof approximately 1 hour, to produce the treated catalyst sample of thisExample 7 having a third hydration state. The proton density of thetreated catalyst was 3.16 mmol per gram of catalyst determined inaccordance with the NMR Procedure for Determining Proton Density,described above, at the Specified NMR Pretreatment Temperature of 150°C.

A 0.5 gram portion of the treated catalyst of this Example 7 was testedin accordance with Catalyst Reactivity Testing Procedure at theSpecified Ex-situ Drying Temperature of 150° C. and the SpecifiedIn-situ Drying Temperature of 150° C. The Catalyst Selectivity of thiscatalyst sample was 7.81, determined as the weight ratio of IPB/DIPB.The Catalyst Activity of this catalyst sample was 251.

The PDI of the catalyst sample of this Example 7 was determined to be1.22, and represents a 22% increase in proton content (determined asmmol of protons per gram of catalyst), as compared to the catalystsample of Example 6. The Catalyst Selectivity (IPB/DIPB) of the catalystsample of Example 7 displayed an increase of 32%, and the CatalystActivity decreased only slightly to 91% of that of the catalyst inExample 6.

Example 8

The catalyst sample of this example comprised 65 wt % MCM-22 and 35 wt %alumina and its proton density was determined in accordance with the NMRProcedure for Determining Proton Density, described above, at theSpecified NMR Pretreatment Temperature of 250° C. The proton density was1.46 mmol per gram of catalyst (first hydration state).

A 1.0 gram portion of the catalyst sample of this Example 8 was testedin accordance with Catalyst Reactivity Testing Procedure at theSpecified Ex-situ Drying Temperature of 250° C. and the SpecifiedIn-situ Drying Temperature of 170° C. The Catalyst Selectivity of thecatalyst sample was 5.46, determined as the weight ratio ofisopropylbenzene to diisopropylbenzene (IPB/DIPB). The Catalyst Activityof this catalyst sample was 272.

Example 9

A portion of the catalyst sample of Example 8 that had become at leastpartially deactivated was regenerated according to the followingtwo-step procedure. First, the catalyst sample was heated to atemperature of 385° C. in an atmosphere having less than 2.0 vol. %hydrogen and hydrocarbons. The oxygen concentration was initiallyincreased to 0.4 vol. %, and then increased again to 0.7 vol. % whilethe maximum catalyst temperature was maintained at 467° C. Second, thecatalyst was heated to 450° C. in 101 kPa-a (1 atmosphere) having anoxygen concentration of 0.7 vol. %, which was increased to 7.0 vol. %while the maximum catalyst temperature was maintained at 510° C.

This catalyst sample was then treated according to Proton ContentAdjustment Technique #1 at a Contact Time of approximately 1 hour, toproduce the treated catalyst of this Example 9 having a third hydrationstate. The proton density of the treated catalyst was 1.97 mmol per gramof catalyst (third hydration state), determined in accordance with theNMR Procedure for Determining Proton Density, described above, at theSpecified NMR Pretreatment Temperature of 250° C.

A 1.0 gram portion of the treated catalyst sample of this Example 9 wastested in accordance with Catalyst Reactivity Testing Procedure at theSpecified Ex-situ Drying Temperature of 250° C. and the SpecifiedIn-situ Drying Temperature of 170° C. The Catalyst Selectivity of thiscatalyst sample was 6.29, determined as the weight ratio IPB/DIPB. TheCatalyst Activity of this catalyst sample was 174.

The PDI of the catalyst sample of Example 9 was determined to be 1.35,and represents a 35% increase in the proton content (determined as mmolof protons per gram of catalyst), as compared to the catalyst sample ofExample 8. The Catalyst Selectivity (IPB/DIPB) of the catalyst sample ofthis Example 9 displayed a 15% increase, and the Catalyst Activity wasstill 64% of that of the catalyst of Example 8.

Example 10

The catalyst sample described in Example 6 was treated in accordancewith Proton Content Adjustment Technique #2 at a Contact Temperature of220° C. and a Contact Pressure of 445 kPa-a (50 psig) in nitrogen thatwas saturated with water vapor. The resulting catalyst sample was thentreated in accordance with to Proton Content Adjustment Technique #1, toproduce the treated catalyst of this Example 10 having a third hydrationstate. The proton density of this treated catalyst sample was determinedin accordance with the NMR Procedure for Determining Proton Density,described above, at the Specified NMR Pretreatment Temperature of 150°C. The proton density was 2.67 mmol per gram of catalyst (thirdhydration state).

A 0.5 gram portion of the treated catalyst sample of this Example 10 wastested in accordance with Catalyst Reactivity Testing Procedure at theSpecified Ex-situ Drying Temperature of 150° C. and the SpecifiedIn-situ Drying Temperature of 150° C. The Catalyst Selectivity of thiscatalyst sample was 7.09, determined as the weight ratio IPB/DIPB. TheCatalyst Activity of this catalyst sample was 244.

The PDI of the catalyst sample of this Example 10 was determined to be1.03, and represents a 3% increase in the proton content (determined asmmol of protons per gram of catalyst) as compared to the catalyst sampleof Example 6. The Catalyst Selectivity (IPB/DIPB) of the catalyst sampleof Example 10 displayed an increase of 20%, and the catalyst activitydecreased only slightly to 89% of that of the catalyst of Example 6.

Example 11 Comparative

The catalyst sample of this Example 11 comprised porous non-crystallinetungsten-zirconia (WZrO₂) and its proton density was determined inaccordance with the NMR Procedure for Determining Proton Density,described above, at the Specified NMR Pretreatment Temperature of 250°C. The proton density was 0.37 mmol per gram of catalyst (firsthydration state).

A 0.5 gram portion of the catalyst sample of this Example 11 was testedin accordance with Catalyst Reactivity Testing Procedure at theSpecified Ex-situ Drying Temperature of 250° C. and the SpecifiedIn-situ Drying Temperature of 170° C. The Catalyst Selectivity was13.70, determined as the weight ratio of isopropylbenzene todiisopropylbenzene (IPB/DIPB). The Catalyst Activity of this catalystsample was 1.

Example 12 Comparative

The catalyst sample of Example 11 was treated in accordance with theProton Content Adjustment Technique #1 at a Contact Time ofapproximately 1 hour, to produce a treated catalyst sample of thisExample 12 having a third hydration state. The proton density of thetreated catalyst sample was 0.41 mmol per gram of catalyst (thirdhydration state), determined in accordance with the NMR Procedure forDetermining Proton Density, described above, at the Specified NMRPretreatment Temperature of 250° C.

A 0.5 gram portion of the treated catalyst of this Example 12 was testedin accordance with Catalyst Reactivity Testing Procedure at theSpecified Ex-situ Drying Temperature of 250° C. and the SpecifiedIn-situ Drying Temperature of 170° C. The Catalyst Selectivity of thiscatalyst sample was 9.62, determined as the weight ratio IPB/DIPB. TheCatalyst Activity of this catalyst sample was 1.

The PDI of the catalyst sample of Example 12 was determined to be 1.11,and represents an 11% increase in the proton content (determined as mmolof protons per gram of catalyst), as compared to the catalyst of Example11. However, the Catalyst Selectivity (IPB/DIPB) of the catalyst sampleof this Example 12 displayed a 29.8% decrease, as compared to thecatalyst sample of Example 11. The Catalyst Activity remained the sameas the catalyst sample of Example 11.

All patents, patent applications, test procedures, priority documents,articles, publications, manuals, and other documents cited herein arefully incorporated by reference for all jurisdictions in which suchincorporation is permitted.

When numerical lower limits and numerical upper limits are listedherein, ranges from any lower limit to any upper limit are contemplated.

While the illustrative embodiments of the invention have been describedwith particularity, it will be understood that various othermodifications will be apparent to and may be readily made by thoseskilled in the art without departing from the spirit and scope of theinvention. Accordingly, it is not intended that the scope of the claimsappended hereto be limited to the examples and descriptions set forthherein but rather that the claims be construed as encompassing all thefeatures of patentable novelty which reside in the present invention,including all features which would be treated as equivalents thereof bythose skilled in the art to which the invention pertains.

1. A method for producing a catalyst composition, said method comprisingthe steps of: (a) providing a first catalyst comprising an acidic,porous crystalline material, said first catalyst having a first protondensity; (b) contacting said first catalyst of step (a) with water inliquid or gaseous form at a contact temperature up to about 500° C., toadd protons and generate a second catalyst having a second protondensity, wherein the value of said second proton density is greater thansaid value of said first proton density when said values are measuredunder the same conditions; and (c) drying said second catalyst of step(b) at a drying temperature of up to about 550° C., to remove at least aportion of said protons from said second catalyst and generate saidcatalyst composition having a third proton density, wherein the value ofsaid third proton density is between said value of said first protondensity and said value of said second proton density when said valuesare measured under the same conditions.
 2. The method of claim 1,wherein the catalytic activity of said third catalyst is greater thanthe catalytic activity of said second catalyst.
 3. The method of claim1, wherein the acidic, porous crystalline material is selected from thegroup consisting of MWW structure type material, zeolite Beta andmixtures thereof.
 4. The method of claim 3, wherein said MWW structuretype material is selected from the group consisting of MCM-22, PSH-3,SSZ-25, ERB-1, ITQ-1, ITQ-2, ITQ-30, MCM-36, MCM-49, MCM-56 and mixturesthereof.
 5. The method of claim 1, wherein the first catalyst furthercomprises a binder, said binder comprises an inorganic material selectedfrom the group consisting of clay, silica, alumina, metal oxide andmixtures thereof.
 6. The method of claim 1, wherein step (b) isconducted at a contact temperature of from about 1° C. to about 99° C.for from about 1 minute to about 60 minutes
 7. The method of claim 1,wherein step (c) is conducted at a drying temperature of from about 100°C. to about 200° C. for from about 0.01 to about 24 hours.
 8. The methodof claim 1, wherein said catalyst composition resulting from step (c)has a Proton Density Index of from greater than 1.0 to less than 2.0. 9.The method of claim 8, wherein said catalyst composition resulting fromstep (c) has a Proton Density Index of from about 1.01 to about 1.85.10. The method of claim 1, wherein said third proton density is greaterthan 2.24 mmol protons per gram.
 11. The method of claim 1, wherein saidacidic, porous crystalline material has an average particle size of fromabout 0.05 to about 200 microns.
 12. A catalyst composition comprisingan acidic, porous crystalline material having a structure selected fromthe group consisting of MCM-22, MCM-36 and MCM-56, wherein said acidic,porous crystalline material having a proton density of greater than 2.24mmol protons per gram.
 13. The catalyst composition of claim 12 having aProton Density Index of from greater than 1.0 to about 2.0.
 14. Acatalyst composition comprising an acidic, porous crystalline materialhaving the structure of MCM-49, said acidic, porous crystalline materialhaving a proton density of greater than 2.14 mmol protons per gram. 15.The catalyst composition of claim 14 having a Proton Density Index offrom greater than 1.0 to about 2.0.
 16. A catalyst compositioncomprising an acidic, porous crystalline material having the structureof zeolite Beta, said acidic, porous crystalline material having aproton density of greater than 3.10 mmol protons per gram.
 17. Thecatalyst composition of claim 16 having a Proton Density Index of fromgreater than 1.0 to about 2.0.